The Fintech RN Build Checklist

1. Real-time data layer — websocket fan-out with reconnection + stale detection
2. Charting — Skia or bust; SVG won't hit 60fps on dense candles
3. Auth — Sign in with Apple is mandatory for App Store approval if you offer any third-party login
4. OTA strategy — fingerprint discipline (see the trap post)
5. Offline/loading states — spotty data in a trading app reads as "the app is lying"
6. Haptics — trade confirmations need tactile feedback
7. App Intents — iOS 27 Siri surface
8. Error tracking — Sentry from day one
9. Review-readiness — Apple's fintech review is strict; have entity docs ready

Stock Picks shipped all nine — the ones we shipped late are the ones that cost us.